When a clock source is connected to multiple nodes / endpoints, the
current USB-audio driver tries to set up at each time one of them is
configured. Although it reads the current rate and updates only if it
differs, some devices seem unhappy with this behavior and spew the
errors when reading/updating the rate unnecessarily.
This patch tries to reduce the redundant clock setup by introducing a
refcount for each clock source. When the stream is actually running,
a clock rate is "locked", and it bypasses the clock and/or refuse to
change any longer.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215934
Link: https://lore.kernel.org/r/20220516104807.16482-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
For making easier to test, add the new quirk_flags bits 17 and 18 to
enable and disable the generic implicit feedback mode. The bit 17 is
equivalent with implicit_fb=1 option, applying the generic implicit
feedback sync mode. OTOH, the bit 18 disables the implicit fb mode
forcibly.
Link: https://lore.kernel.org/r/20220421064101.12456-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In the previous fix, we increased the max buffer bytes from 1MB to 4MB
so that we can use bigger buffers for the modern HiFi devices with
higher rates, more channels and wider formats. OTOH, extending this
has a concern that too big buffer is allowed for the lower rates, less
channels and narrower formats; when an application tries to allocate
as big buffer as possible, it'll lead to unexpectedly too huge size.
Also, we had a problem about the inconsistent max buffer and period
bytes for the implicit feedback mode when both streams have different
channels. This was fixed by the (relatively complex) patch to reduce
the max buffer and period bytes accordingly.
This is an alternative fix for those, a patch to kill two birds with
one stone (*): instead of increasing the max buffer bytes blindly and
applying the reduction per channels, we simply use the hw constraints
for the buffer and period "time". Meanwhile the max buffer and period
bytes are set unlimited instead.
Since the inconsistency of buffer (and period) bytes comes from the
difference of the channels in the tied streams, as long as we care
only about the buffer (and period) time, it doesn't matter; the buffer
time is same for different channels, although we still allow higher
buffer size. Similarly, this will allow more buffer bytes for HiFi
devices while it also keeps the reasonable size for the legacy
devices, too.
As of this patch, the max period and buffer time are set to 1 and 2
seconds, which should be large enough for all possible use cases.
(*) No animals were harmed in the making of this patch.
Fixes: 98c27add5d ("ALSA: usb-audio: Cap upper limits of buffer/period bytes for implicit fb")
Fixes: fee2ec8cce ("ALSA: usb-audio: Increase max buffer size")
Link: https://lore.kernel.org/r/20220412130740.18933-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The current limit of max buffer size 1MB seems too small for modern
devices with lots of channels and high sample rates.
Let's make bigger, 4MB.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220407212740.17920-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In the implicit feedback mode, some parameters are tied between both
playback and capture streams. One of the tied parameters is the
period size, and this can be a problem if the device has different
number of channels to both streams. Assume that an application opens
a playback stream that has an implicit feedback from a capture stream,
and it allocates up to the max period and buffer size as much as
possible. When the capture device supports only more channels than
the playback, the minimum period and buffer sizes become larger than
the sizes the playback stream took. That is, the minimum size will be
over the max size the driver limits, and PCM core sees as if no
available configuration is found, returning -EINVAL mercilessly.
For avoiding this problem, we have to look through the counter part of
audioformat list for each sync ep, and checks the channels. If more
channels are found there, we reduce the max period and buffer sizes
accordingly.
You may wonder that the patch adds only the evaluation of channels
between streams, and what about other parameters? Both the format and
the rate are tied in the implicit fb mode, hence they are always
identical.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215792
Fixes: 5a6c3e11c9 ("ALSA: usb-audio: Add hw constraint for implicit fb sync")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220407211657.15087-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Fix:
sound/usb/midi.c: In function ‘snd_usbmidi_out_endpoint_create’:
sound/usb/midi.c:1389:2: error: case label does not reduce to an integer constant
case USB_ID(0xfc08, 0x0101): /* Unknown vendor Cable */
^~~~
See https://lore.kernel.org/r/YkwQ6%2BtIH8GQpuct@zn.tnic for the gory
details as to why it triggers with older gccs only.
[ A slight correction with parentheses around the argument by tiwai ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220405151517.29753-3-bp@alien8.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
For the RODE NT-USB the lowest Playback mixer volume setting mutes the
audio output. But it is not reported as such causing e.g. PulseAudio to
accidentally mute the device when selecting a low volume.
Fix this by applying the existing quirk for this kind of issue when the
device is detected.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220311201400.235892-1-lars@metafoo.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The Focusrite Scarlett Gen 2/3 interfaces with internal mixers have a
"standalone" mode. When the interface is not connected to a USB host
and standalone mode is enabled, the interface will pass audio as
previously configured. This patch adds an ALSA control to allow
enabling/disabling that mode.
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Link: https://lore.kernel.org/r/cd88871c5e77abd5c23a4758a1f2ec9fd427fd69.1646578164.git.g@b4.vu
Signed-off-by: Takashi Iwai <tiwai@suse.de>
scarlett2_config_items[] contains the parameters for the configuration
items. The driver previously had two sets of configurations items; one
for devices with no mixer, and one for devices with a mixer. This
patch splits the latter into two (one set for Gen 2 devices and one
set for Gen 3 devices) in preparation for a new item (standalone)
which is present in both but with a different offset.
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Link: https://lore.kernel.org/r/20969f9ea500684e978c87067fbdc7e73de1f6ed.1646578164.git.g@b4.vu
Signed-off-by: Takashi Iwai <tiwai@suse.de>
New device id for Corsair Virtuoso SE RGB Wireless that currently is not
in the mixer_map. This entry in the mixer_map is necessary in order to
label its mixer appropriately and allow userspace to pick the correct
volume controls. For instance, my own Corsair Virtuoso SE RGB Wireless
headset has this new ID and consequently, the sidetone and volume are not
working correctly without this change.
> sudo lsusb -v | grep -i corsair
Bus 007 Device 011: ID 1b1c:0a40 Corsair CORSAIR VIRTUOSO SE Wireless Gam
idVendor 0x1b1c Corsair
iManufacturer 1 Corsair
iProduct 2 CORSAIR VIRTUOSO SE Wireless Gaming Headset
Signed-off-by: Reza Jahanbakhshi <reza.jahanbakhshi@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220304212303.195949-1-reza.jahanbakhshi@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The default mixer resume code treats the errors at restoring the
modified mixer items as a fatal error, and it returns back to the
caller. This ends up in the resume failure, and the device will be
come unavailable, although basically those errors are intermittent and
can be safely ignored.
The problem itself has been present from the beginning, but it didn't
hit usually because the code tries to resume only the modified items.
But now with the recent commit to forcibly initialize each item at the
probe time, the problem surfaced more often, hence it appears as a
regression.
This patch fixes the regression simply by ignoring the errors at
resume.
Fixes: b96681bd58 ("ALSA: usb-audio: Initialize every feature unit once at probe time")
Cc: <stable@vger.kernel.org>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215561
Link: https://lore.kernel.org/r/20220214125711.20531-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Commit 83b7dcbc51 introduced a generic
implicit feedback parser, which fails to execute for M-Audio FastTrack
Ultra sound cards. The issue is with the ENDPOINT_SYNCTYPE check in
add_generic_implicit_fb() where the SYNCTYPE is ADAPTIVE instead of ASYNC.
The reason is that the sync type of the FastTrack output endpoints are
set to adaptive in the quirks table since commit
65f04443c9.
Fixes: 83b7dcbc51 ("ALSA: usb-audio: Add generic implicit fb parsing")
Signed-off-by: Matteo Martelli <matteomartelli3@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220211224913.20683-2-matteomartelli3@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The variable c is being initialized in an outer for-loop and also
re-initialized inside an inner for-loop. The first initialization
is redundant and can be removed.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220207140617.341172-1-colin.i.king@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This device provides both audio and video. The original quirk added in
commit 48827e1d6a ("ALSA: usb-audio: Add quirk for VF0770") used
USB_DEVICE to match the vendor and product ID. Depending on module order,
if snd-usb-audio was asked first, it would match the entire device and
uvcvideo wouldn't get to see it. Change the matching to USB_AUDIO_DEVICE
to restore uvcvideo matching in all cases.
Fixes: 48827e1d6a ("ALSA: usb-audio: Add quirk for VF0770")
Reported-by: Jukka Heikintalo <heikintalo.jukka@gmail.com>
Tested-by: Jukka Heikintalo <heikintalo.jukka@gmail.com>
Reported-by: Paweł Susicki <pawel.susicki@gmail.com>
Tested-by: Paweł Susicki <pawel.susicki@gmail.com>
Cc: <stable@vger.kernel.org> # 5.4, 5.10, 5.14, 5.15
Signed-off-by: Jonas Hahnfeld <hahnjo@hahnjo.de>
Link: https://lore.kernel.org/r/20220131183516.61191-1-hahnjo@hahnjo.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
clang static analysis reports this representative issue
mixer.c:1548:35: warning: Assigned value is garbage or undefined
ucontrol->value.integer.value[0] = val;
^ ~~~
The filter_error() macro allows errors to be ignored.
If errors can be ignored, initialize variables
so garbage will not be used.
Fixes: 48cc429735 ("ALSA: usb-audio: Filter error from connector kctl ops, too")
Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20220126182142.1184819-1-trix@redhat.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows that,
in the worst scenario, could lead to heap overflows.
Also, address the following sparse warnings:
sound/usb/mixer_scarlett_gen2.c:1064:28: warning: using sizeof on a flexible structure
sound/usb/mixer_scarlett_gen2.c:1065:29: warning: using sizeof on a flexible structure
Link: https://github.com/KSPP/linux/issues/174
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220120211600.GA28841@embeddedor
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The USB audio device 0db0:419c based on the Realtek ALC4080 chip exposes
all playback volume controls as "PCM". This is makes distinguishing the
individual functions hard.
The added mapping distinguishes all playback volume controls as their
respective function:
- Speaker - for back panel output
- Frontpanel Headphone - for front panel output
- IEC958 - for digital output on the back panel
This clarifies the individual volume control functions for users.
Signed-off-by: Johannes Schickel <lordhoto@gmail.com>
Link: https://lore.kernel.org/r/20220115140257.8751-1-lordhoto@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Olivia Mackintosh has posted to alsa-devel reporting that
there's a potential bug that could break mixer quirks for Pioneer
devices introduced by 6d27788160
"ALSA: usb-audio: Add support for the Pioneer DJM 750MK2
Mixer/Soundcard".
This happened because the DJM 750 MK2 was added last to the Pioneer DJM
device table index and defined as 0x4 but was added to snd_djm_devices[]
just after the DJM 750 (MK1) entry instead of last, after the DJM 900
NXS2. This escaped review.
To prevent that from ever happening again, Takashi Iwai suggested to use
C99 array designators in snd_djm_devices[] instead of simply reordering
the entries.
Fixes: 6d27788160 ("ALSA: usb-audio: Add support for the Pioneer DJM 750MK2")
Reported-by: Olivia Mackintosh <livvy@base.nu>
Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
Link: https://lore.kernel.org/r/Yau46FDzoql0SNnW@geday
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The recent change made mistakenly the stream for capture started at
prepare stage. Add the stream direction check to avoid it.
Fixes: 9c9a3b9da8 ("ALSA: usb-audio: Rename early_playback_start flag with lowlatency_playback")
Link: https://lore.kernel.org/r/20211119102629.7476-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The recent regression report revealed that the judgment of the
low-latency playback mode based on the runtime->stop_threshold cannot
work reliably at the prepare stage, as sw_params call may happen at
any time, and PCM dmix actually sets it up after the prepare call.
This ended up with the stall of the stream as PCM ack won't be issued
at all.
For addressing this, check the free-wheeling mode again at the PCM
trigger right before starting the stream again, and allow switching to
the non-LL mode at a late stage.
Fixes: d5f871f89e ("ALSA: usb-audio: Improved lowlatency playback support")
Reported-and-tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/20211117161855.m45mxcqszkfcetai@box.shutemov.name
Link: https://lore.kernel.org/r/20211119102459.7055-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Some devices do mute the volume at the minimal volume, and for such
devices, we need to set SNDRV_CTL_TLVT_DB_MINMAX_MUTE to the TLV
information. It corresponds to setting usb_mixer_elem_info.min_mute
flag in the USB-audio driver.
This patch adds a new field min_mute in usbmix_dB_map so that the
mixer map entry can pass the flag.
Link: https://lore.kernel.org/r/20211116065415.11159-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The values in usbmix_dB_map should be rather signed while we're using
u32. As the copied target (usb_mixer_elem_info.dBmin and dBmax) is
int, let's make them also int.
Link: https://lore.kernel.org/r/20211116065415.11159-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Adding the Line6 HX-Stomp XL USB_ID as it needs this fixed frequency
quirk as well.
The device is basically just the HX-Stomp with some more buttons on
the face. I've done some recording with it after adding it, and it
seems to function properly with this fix. The Midi features appear to
be working as well.
[ a coding style fix and patch reformat by tiwai ]
Signed-off-by: Jason Ormes <skryking@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211030200405.1358678-1-skryking@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Add another device ID for JBL Quantum 400. It requires the same quirk as
other JBL Quantum devices.
Signed-off-by: Alexander Tsoy <alexander@tsoy.me>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211030174308.1011825-1-alexander@tsoy.me
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Add the missing endpoint max-packet sanity check to probe() to avoid
division by zero in alloc_stream_buffers() in case a malicious device
has broken descriptors (or when doing descriptor fuzz testing).
Note that USB core will reject URBs submitted for endpoints with zero
wMaxPacketSize but that drivers doing packet-size calculations still
need to handle this (cf. commit 2548288b4f ("USB: Fix: Don't skip
endpoint descriptors with maxpacket=0")).
Fixes: 63978ab3e3 ("sound: add Edirol UA-101 support")
Cc: stable@vger.kernel.org # 2.6.34
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211026095401.26522-1-johan@kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
USB control and bulk message timeouts are specified in milliseconds and
should specifically not vary with CONFIG_HZ.
Fixes: c6d43ba816 ("ALSA: usb/6fire - Driver for TerraTec DMX 6Fire USB")
Cc: stable@vger.kernel.org # 2.6.39
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211025121142.6531-2-johan@kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The pointer cs_desc return from snd_usb_find_clock_source could
be null, so there is a potential null pointer dereference issue.
Fix this by adding a null check before dereference.
Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>
Link: https://lore.kernel.org/r/20211024111736.11342-1-cyeaa@connect.ust.hk
Signed-off-by: Takashi Iwai <tiwai@suse.de>
When a Jieli Technology USB Webcam is connected, the video part works
well, but the mic sound is speeded up. On dmesg there are messages
about different rates from the runtime rates, warnings about volume
resolution and lastly, the log is filled, every 5 seconds, with
retire_capture_urb error messages.
The mic works only when ep packet size is set to wMaxPacketSize (normal
sound and no more retire_capture_urb error messages). Skipping reading
sample rate, fixes the messages about different rates and forcing a volume
resolution, fixes warnings about volume range. I have arbitrarily choosed
the value (16): I read in a comment that there should be no more than 255
levels, so 4096 (max volume) / 16 = 0-255.
Signed-off-by: Marco Giunta <giun7a@gmail.com>
Link: https://lore.kernel.org/r/20211018162552.12082-1-giun7a@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
As per discussion at: https://github.com/szszoke/sennheiser-gsp670-pulseaudio-profile/issues/13
The GSP670 has 2 playback and 1 recording device that by default are
detected in an incompatible order for alsa. This may have been done to make
it compatible for the console by the manufacturer and only affects the
latest firmware which uses its own ID.
This quirk will resolve this by reordering the channels.
Signed-off-by: Brendan Grieve <brendan@grieve.com.au>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211015025335.196592-1-brendan@grieve.com.au
Signed-off-by: Takashi Iwai <tiwai@suse.de>
So far we used to read the current value of the mixer element
dynamically at the first access, and the error from a GET_CUR message
is treated as a fatal error (unless QUIRK_IGNORE_CTL_ERROR is set).
It's rather inconvenient, as most of GET_CUR errors are no fatal, and
we can continue operation with assumption of some fixed value.
This patch makes the USB-audio driver to change the behavior at probe
time; now it tries to initialize the current value of each mixer
element that is built from a feature unit (those for typically for
mixer volumes and switches). When a read failure happens, it tries to
set the known minimum value. After that point, a cached value is used
always, hence we won't hit GET_CUR message error any longer.
The error from GET_CUR message is still shown as a warning normally,
but only once at the probe time, and it'll keep operating. If the
message is confirmed to be harmless, it can be shut up by
QUIRK_IGNORE_CTL_ERROR quirk flag, too.
Tested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20211014130636.17860-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The error from snd_usb_lock_shutdown() indicates that the device is
disconnected, hence it makes no sense to show any further control
message error in get_ctl_value_v2(). Return the error directly
instead.
Tested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20211014130636.17860-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The error message in get_ctl_value_v2() (for UAC2/3) is shown via
KERN_ERR level but it was intended to be rather a debug message as
seen in get_ctl_value_v1() (for UAC1). This patch downgrade the
printk level.
Tested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20211014130636.17860-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
A back-merge of 5.15 branch into 5.16-devel branch for further
development of USB and ALSA core stuff that depends on 5.15 fixes.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The Shciit Hel device responds to the ctl message for the mic capture
switch with a timeout of -EPIPE:
usb 7-2.2: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x1100, type = 1
usb 7-2.2: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x1100, type = 1
usb 7-2.2: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x1100, type = 1
usb 7-2.2: cannot get ctl value: req = 0x81, wValue = 0x100, wIndex = 0x1100, type = 1
This seems safe to ignore as the device works properly with the control
message quirk, so add it to the quirk table so all is good.
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: alsa-devel@alsa-project.org
Cc: linux-usb@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/YWgR3nOI1osvr5Yo@kroah.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The device advertises 8 formats, but only a rate of 48kHz is honored
by the hardware and 24 bits give chopped audio, so only report the
one working combination. This fixes out-of-the-box audio experience
with PipeWire which otherwise attempts to choose S24_3LE (while
PulseAudio defaulted to S16_LE).
Signed-off-by: Jonas Hahnfeld <hahnjo@hahnjo.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211012200906.3492-1-hahnjo@hahnjo.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The recent support for the improved low-latency playback mode applied
the SNDRV_PCM_INFO_EXPLICIT_SYNC flag for the target streams, but this
was a slight overkill. The use of the flag above disables effectively
both PCM status and control mmaps, while basically what we want to
track is only about the appl_ptr update.
For less restriction, use a more proper flag,
SNDRV_PCM_INFO_SYNC_APPLPTR instead, which disables only the control
mmap.
Fixes: d5f871f89e ("ALSA: usb-audio: Improved lowlatency playback support")
Link: https://lore.kernel.org/r/20211011103650.10182-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The kernel already has support for very similar Pioneer djm products
and this work is based on that.
Added device to quirks-table.h and added control info to
mixer_quirks.c.
Tested on my hardware and all working.
Signed-off-by: William Overton <willovertonuk@gmail.com>
Link: https://lore.kernel.org/r/20211010145841.11907-1-willovertonuk@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
When a stream is in the implicit feedback mode, it's more or less tied
with a capture stream. Passing SNDRV_PCM_INFO_JOINT_DUPLEX may help
for user-space to understand the situation.
Link: https://lore.kernel.org/r/20211007083528.4184-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
